Applications of Colloids

Q.

Which one of the following statements is correct :

i) Brownian movement is more pronounced for smaller particles than for bigger ones

ii) Sols of metal sulphides are lyophilic

iii) Schulze-Hardey law states, the bigger the size of the ion, the greater is its coagulating power

iv) One would be expect charcoal to adsorb chlorine more strongly hydrogen sulphide

1. i, iii & iv
2. ii, iv
3. i, iii
4. i , iii

Q. Which of the following are applications of colloids?

1. Formation of delta
2. Cottrel precipitator
3. Alloying
4. Ideal gas equation

Q.

Which one of the following is not a surfactant

1. 

2. 

3. 

4. 

Q.

Alum is used to purify water since it acts as

1. De-odorant

2. Coagulant

3. Softener

4. Bactericide

Q. The coagulation of 100ml of colloidal solution of gold is completely prevented by addition of 0.25g of a substance of X to it before adding 1ml of 10% NaCl solution. the gold number of "X" is-

1. 2.5
2. 0.25
3. 25
4. 250

Q. Silver iodide is used in bringing about artificial rain because silver iodide

1. has crystal structure similar to ice and leads to coagulation
2. is easily decomposed in presence of sunlight
3. contains iodide ions which are large in size
4. being heavy, its spray brings the water droplets down

Q.

The one having maximum protective power (G.No. = Gold number)

1. Gum Arabic (G.No.15)

2. Gelatin (G.No.0.01)

3. Starch (G.No.25)

4. Engg albumin (G.No.015 to 0.25)

Q. ${10}^{-4}$ g of gelatin is required to be added to 100 $c{m}^3$ of a stanadard gold solution to just prevent its precipitation by addition of 1 $c{m}^3$ of 10% NaCl solution to it. Hence, gold number of gelatin is?

1. 0.1
2. 10
3. 1
4. 0.01

Q.

Which one is not a colloidal solution

1. Ink
2. Air
3. Smoke
4. Blood

Q.

Which of the following electrolytes is least effective in causing flocculation of

ferric hydroxide sol

[MNR 1991; UPSEAT 1999]

1. 
2. 
3. 
4.